搜题请搜索小程序“爱下问搜题”
问题 选择题
双曲线
x2
12
-
y2
4
=1的渐近线与圆x2+y2-4x+3=0的位置关系为（　　）
A．相切B．相交但不经过圆心
C．相交且经过圆心D．相离
答案

双曲线

x2
12
-
y2
4
=1的渐近线为 
3
 x±3 y=0，圆x2+y2-4x+3=0 即 （x-2）2+y2=1，

圆心（2，0）到直线 

3
 x±3 y=0的距离为 
|2
3
±0|
3+9
=1（半径），故渐近线与圆相切，

故选A．

单项选择题

The nurse is assigned to care for a postoperative client who has diabetes mellitus. During the assessment interview, the client reports that he’s impotent and says that he’s concerned about its effect on his marriage. In planning this client’s care, the most appropriate intervention would be to

A. encourage the client to ask questions about personal sexuality.
B. provide time for privacy.
C. provide support for the spouse or significant other.
D. suggest referral to a sex counselor or other appropriate professional.
查看答案
单项选择题

如图所示机构曲柄OA长为r，质量不计，绕O轴以匀角速度ω转动；连杆AB长为l，质量为m；作纯滚动的圆盘半径为R，质量为m，则系统的动能为（）。

A．mr2ω2

B．

C．

D．
查看答案